Enermax, a leading maker of power supply units for personal computers, on Wednesday said that virtually all of its currently available mid-range and high-end PSUs will support the low-power states of the forthcoming Intel Core i-series “Haswell” microprocessors. In addition, select previous-gen power supplies will also support the future chip.

It recently transpired that Intel Haswell's C6/C7 power states require a minimum load of 0.05A on the 12V2 rail, whereas many desktop PSUs just cannot provide that low current. Numerous older PSUs, which comply with ATX12V v2.3 design guidelines that only called for a minimum load of 0.5A on the CPU power rail, can be equipped with a less sophisticated internal feedback loop/protection that cannot supply 0.05A to CPU. As a result, unless C6/C7 power states are disabled in the BIOS, PCs with older/cheap PSUs may become unstable when processors enter these states. To make the matters worse, many power supply units do not report minimum currents supported by 12V2 rail. As a result, it is now hard for system makers and end-users to determine whether their PSUs are Intel Core i-series “Haswell” compatible.

Enermax decided to become the first PSU maker to publish the list of Haswell-compatible PSUs. According to the company, all current high-end and mid-range models from Enermax are already prepared for the upcoming Intel processors. They are equipped with a DC-to-DC converter which enables the so-called Zero Load Design. These power supplies will deliver rock-stable voltages even at 0W load. Also the owners of select older Enermax power supplies can be relieved: The manufacturer applies the Zero Load Design already in all high-end power supplies since the Revolution85+ series which was launched in 2008.

The list of Enermax Intel Core i “Haswell”-Compatible PSUs looks as follows: